1. Field of the Invention
A toroidal-type continuously variable transmission according to the present invention is utilized as an automatic transmission apparatus for an automobile, or a transmission apparatus for controlling an operating speed of various industrial machines of a pump and the like.
2. Description of the Related Art
There is known and partially embodied a toroidal-type continuously variable transmission as a kind of a transmission apparatus constituting a kind of a transmission for an automobile. Further, there has been known various conventional continuously variable transmission apparatus each combined with a toroidal-type continuously variable transmission and a planetary gear type transmission. Further, in the various conventional variable transmission apparatus, there is also known a structure that an output side disk is provided with output-side side surfaces, of which a section is in a circular arc shape, at both side surfaces relative to an axial direction, and an input shaft is provided concentrically with a hollow rotating shaft as described in Japanese Patent Unexamined Publications Nos. JP-A-6-174033, JP-A-2002-48205 and JP-A-11-141637, U.S. Pat. No. 6,251,039, U.S. Pat. No. 6,585,619, U.S. Pat. No. 5,607,372 and U.S. Pat. No. 6,099,431 and U.S. Patent Unexamined Publication U.S. 2003/0224895A1.
FIGS. 7 through 8 show a continuously variable transmission apparatus described in U.S. 2003/0224895A1. First, a continuously variable transmission apparatus of the related art will be explained. In FIGS. 7 through 8, positions of sections of one cavity and another cavity differ from each other by 90 degrees relative to a circumferential direction. The continuously variable transmission apparatus comprises a toroidal-type continuously variable transmission 1, first through third respective planetary gear type transmissions 2 through 4, an input shaft 5, a transmitting shaft 6 and an output shaft 7 supported concentrically and rotatably relative to each other. The first and second planetary transmissions 2, 3 are provided in a state of being hung between the input shaft 5 and transmitting shaft 6. The third planetary gear type transmission 4 is provided in a state of being hung between the transmitting shaft 6 and the output shaft 7, respectively.
The toroidal-type continuously variable transmission 1 includes a pair of input side disks 8a, 8b, an output side disk 9 of an integrated type and a plurality of power rollers, 10, 10. The two input side disks 8a, 8b are supported on two portions of the input shaft 5, which portions are separated from each other in an axial direction of the input shaft 5. The input side disks 8a, 8b are concentric with one another and rotate in a synchronized manner. Additionally, the input side disks 8a, 8b, are disposed so that side faces thereof in the axial direction are arc shaped, and are opposed to each other. The output side disk 9 is supported on a middle portion of the input shaft 5 and between the two input side disks 8a, 8b so as to be concentric with the two input side disks 8a, 8b and to rotate relative to the two input side disks 8a, 8b. The side faces of the output side disk 9 in the axial direction have a section that is in an arc shape, and are opposed to respective ones of the side faces of the input side disks 8a, 8b. 
Pluralities of the respective power rollers 10, 10 are pinched between the side faces in the axial direction of the output side disk 9 and the one side face in the axial direction of the input side disks 8a, 8b to be able to transmit power from the two input side disks 8a, 8b to the output side disk 9. The respective power rollers 10, 10 are rotatably supported respectively on inner side faces of trunnions 12, 12 constituting supporting members. Pivot shafts provided at both end portions of the respective trunnions 12, 12 are supported by supporting plates 13a, 13b swingably and displaciably in the axial directions. Further, the two supporting plates 13a, 13b are supported by supporting posts 14a, 14b fixed to inside of a casing 15.
Both end portions in the axial direction of the output side disk 9 are rotatably supported by a pair of thrust angular ball bearings 11, 11. Accordingly, the pair of supporting posts 14a, 14b provided concentrically with each other are connected by holding rings 16, of which a shape is a circular ring, at an opposite side in radial direction of the input shaft 5. The input shaft 5 is inserted through inner sides of the holding rings 16. Further, the respective thrust angular ball bearings 11, 11 are provided between the respective holding rings 16, 16, which are provided in the respective cavities, and the both end faces in the axial direction of the output side disk 9.
The output side disk 9 is engaged with a base end portion (left end portions in FIGS. 7 through 8) of a hollow rotating shaft 17 by a spline. In addition, a rotational force of the output side disk 9 is made to be able to be outputted by inserting the hollow rotating shaft 17 through an inner side of the input side disk 8b on a side remote from an engine (right sides of FIGS. 7 through 8). Further, a first sun gear 18 for constituting the first planetary gear type transmission 2 is fixedly provided at a front end portion (right end portions of FIGS. 7 through 8) of the hollow rotating shaft 17 projected from an outer side face of the input side disk 8b. 
Meanwhile, a first carrier 19 is provided to be hung between the input portion of a front end portion (right end portions of FIGS. 7 through 8) of the input shaft 5, which is projected from the hollow rotating shaft 17, and the input side disk 8b so as to rotate the input side disk 8b and the input shaft 5 synchronizingly with each other. Planetary gears 20 through 22 for constituting the first and the second planetary gear type transmissions 2, 3 each constituting a double pinion type are rotatably supported at positions of both side faces in an axial direction of the first carrier 19 having equal intervals in a circumferential direction (generally, positions of three to four portions). A first ring gear 23 is rotatably supported by a surrounding of one half portion (right half portions of FIGS. 7 through 8) of the first carrier 19.
In the respective planetary gears 20 through 22, the planetary gear 20 provided on an inner side in a radial direction of the first carrier 19, which is proximate to the toroidal-type continuously variable transmission 1 (proximate to left sides of FIGS. 7 through 8), meshes with the first sun gear 18. Further, the planetary gear 21 provided on an inner side in the radial direction of the first carrier 19 at a side remote from the toroidal-type continuously variable transmission 1 (right sides of FIGS. 7 through 8) meshes with a second sun gear 24 fixedly provided at a base end portion (left end portion of FIG. 7) of transmitting shaft 6. The remaining planetary gear 22 provided on an outer side in the radial direction of the first carrier 19 is made to be larger in an axial direction than the planetary gears 20, 21 provided on the inner side in an axial direction and meshes with the two gears 20, 21. Further, the remaining planetary gear 22 and the first ring gear 23 are brought in mesh with each other.
Meanwhile, a second carrier 25 for constituting the third planetary gear type transmission 4 is fixedly coupled to a base end portion (left end portion of FIG. 7) of the output shaft 7. Further, the second carrier 25 and the first ring gear 23 are coupled via a low speed clutch 26. Further, a third sun gear 27 is fixedly provided to a portion proximate to a front side (proximate to right ends of FIGS. 7 through 8) of the transmitting shaft 6. Further, a second ring gear 28 is arranged at a surrounding of the third sun gear 27. A high speed clutch 29 is provided between the second ring gear 28 and a fixed portion of the casing 15 or the like. A plurality of sets of planetary gears 30, 31 arranged between the second ring gear 28 and the third sun gear 27 are rotatably supported by the second carrier 25. The respective planetary gears 30, 31 are brought in mesh with each other, the planetary gear 30 provided on an inner side in a radial direction of the second carrier 25 is brought in mesh with the third sun gear 27, and the planetary gear 31 similarly provided on an outer side thereof is brought in mesh with the second ring gear 28, respectively.
In the case of the continuously variable transmission apparatus constituted as described above, power transmitted to the integral type output side disk 9 from the input shaft 5 via the input side disks 8a, 8b and the respective power rollers 10, 10 is outputted by way of the hollow rotating shaft 17. Further, in a low speed mode of connecting the low speed clutch 26 and disconnecting the high speed clutch 29, by changing transmission ratio of the toroidal-type continuously variable transmission 1, a rotational speed of the output shaft 7 is made to be able to be converted regularly and reversely by interposing a stationary state while making a rotational speed of the input shaft 5 constant. That is, under the state, a differential component disposed between the first carrier 19 rotated in a regular direction along with the input shaft 5 and the first sun gear 18 rotated in a reverse direction along with the hollow rotating shaft 17 is transmitted from the first ring gear 23 to the output shaft 7 via the low speed clutch 26 and the second carrier 25. Under the state, the output shaft 7 can be stopped by setting the transmission ratio of the toroidal-type continuously variable transmission 1 to a predetermined value, further the output shaft 7 can be rotated in a direction of moving back a vehicle by changing the transmission ratio of the toroidal-type continuously variable transmission 1 from the predetermined value to a speed increasing side. In contrast, the output shaft 7 can be rotated in a direction of moving forward the vehicle by changing the transmission ratio of the toroidal-type continuously variable transmission 1 from the predetermined value to a speed reducing side.
Further, in a high speed mode of disconnecting the low speed clutch 26 and connecting the high speed clutch 29, the output shaft 7 is rotated in the direction of moving forward the vehicle. That is, under the state, rotation of the planetary gear 20 of the first planetary gear type transmission 2 rotated in accordance with a differential component, which is disposed between the first carrier 19 rotated in a regular direction along with the input shaft 5 and the first sun gear 18 rotated in a reverse direction along with the hollow rotating shaft 17, is transmitted to the planetary gear 21 of the second planetary gear type transmission 3 via the other planetary gear 22, and the rotation of the planetary gear 20 rotate the transmitting shaft 6 via the second sun gear 24. Further, the second carrier 25 and the output shaft 7 coupled with the second carrier 25 are rotated in a forward moving direction by meshing among the third sun gear 27 provided at the front end of the transmitting shaft 6, the second ring gear 28 and the planetary gears 30, 31 constituting the third planetary gear type transmission 4 along with the sun gear 27. Under the state, the more changed the transmission ratio of the toroidal-type continuously variable transmission 1 to the speed increasing side, the faster the rotational speed of the output shaft 7 can be made.
When the toroidal-type continuously variable transmission is embodied including a case of constituting the continuously variable transmission apparatus by combining with the planetary transmission, it is necessary to monitor rotational speeds of respective portions for feeding back the rotational speeds to a controller for controlling the transmission ratio in order to monitor whether a desired transmission ratio is obtained. Particularly, in the case of the toroidal-type continuously variable transmission constituting the above-described continuously variable transmission apparatus, in connecting and disconnecting the two high speed and the low speed clutches 26, 29 for switching the low speed mode and the high speed mode, or in stopping the output shaft 7 while making the rotational speed of the input shaft 5 constant in the low speed mode, it is necessary to strictly restrict the transmission ratio of the toroidal-type continuously variable transmission 1. Meanwhile, since a number of parts are present at an inner portion of the toroidal-type continuously variable transmission, a space for installing a part for detecting the rotational speed is limited. Therefore, it is preferable to be able to constitute a structure for detecting the rotational speeds of the respective portions of the toroidal-type continuously variable transmission as compact as possible.
In view of such a situation, U.S. Pat. No. 6,099,431 describes a structure wherein recessed and projected portions for detecting the rotational speed are formed integrally with the input side disk, on the outer peripheral portion of the input side disk. However, in U.S. Pat. No. 6,099,431, although a structure for detecting the rotational speed of the input side disk is described, there is not described a structure for detecting the rotational speed of the integral type output side disk, in which both side faces in the axial direction are constituted by curved faces having a section in a circular arc shape for being respectively brought into rolling contact with peripheral faces of the power rollers. At a portion of installing such an integrated type output side disk, an extra space is small particularly at a surrounding thereof. Therefore, compact formation is requested for a structure for detecting the rotational speed of the output side disk more than that of the structure for detecting the rotational speed of the input side disk. In JP-A-11-141637, although there is described a structure formed with an output gear for outputting power at an outer peripheral edge portion of the integral type output side disk, it is not described to integrate a structure for detecting the rotational speed at that portion.